Police and fire officials at a news conference yesterday explained that the H-1 freeway's 10-hour closure Saturday was due to a gasoline spill and blamed the 5 1/2 -hour closure Sunday on a fatal motorcycle accident.

At 8:45 a.m. Saturday the Honolulu Fire Department got the report of the spill by a damaged Aloha Petroleum gasoline tanker in a westbound lane.

Fire Capt. Terry Seelig defended the need to close both sides of the freeway, as a volatile vapor cloud travels quickly and close to the ground.

Police began shutting down the H-1 freeway eastbound lanes from the Ewa/Kunia exit at about 9:15 a.m. and eventually closed westbound lanes as well. All lanes were reopened by 7:30 p.m.

State and federal firefighters assisted, applying foam over the approximately 2,500 gallons of spilled fuel.

The tractor's drive shaft had dislodged, puncturing the first compartment of a 5,000-gallon tank on the tractor, which was pulling a second 5,000-gallon tank on a trailer.

The Fire Department left at 1:30 p.m. when the tanker truck was hauled away.

The remaining cleanup of a grassy area was conducted by a private contractor and continued until shortly before 7:30 p.m.

A Department of Health spokeswoman said Aloha Petroleum hired a contractor to remove the contaminated soil, and the freeway had to remain closed to do the work safely.

The 5 1/2 -hour closure of the H-1 freeway Sunday in the westbound lanes near the 7th Avenue overpass was needed to conduct a thorough investigation by HPD's Vehicular Homicide Section, said HPD Maj. Frank Fujii. Police took three hours just to map the accident scene since the debris covered a half-mile. He said an investigation includes interviewing witnesses and photographing the area to reconstruct the scene in case a crime occurred.

A 35-year-old Kapolei man was traveling more than 100 mph when he slammed into a guardrail and was thrown onto the roadway as his 2008 blue and white Suzuki motorcycle continued on. The man then was struck by a car, Fujii said. He was taken in critical condition to the Queen's Medical Center, where he was pronounced dead at 5:06 p.m.